Yup, I checked the Lyman Manual and they do indeed distinguish between the 8X57 J, the 8X57 JR (rimmed) and the 8X57 JS

The 8X57J with a .318 dia bullet and the 8X57 JS with .323 Dia bullets.

Incidently I didn' t post from memory.....the previous data I posted is direct from the Hornady Manual!!!

The Hornady manual does state " Confusion over the 8mm' s nomenclature remains" ..........

guess we' re victims of that confusion....the good news is that you' re not trying to stuff .323 Dia bullets down a .318 Dia barrel!!!